Electronic regulator



ELECTRONIC REGULATOR Original Filed April '7, 1937 WITNESSES: I E INVENTOR 4%, M F'zflnh. Gzz/Ziksezz. Z20. N M a i? 77, ATTORNEY Patented Mar. 17, 1942 ELECTRONIC REGULATOR Finn H. Gulliksen, Wilkinsburg, lla., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Original application April 7, 1931, Serial No.

135,483. Divided and this application June 23,

1939, Serial No. 280,685 7 10 Claims.

My invention relates to electronic regulators, and is particularly adapted for use in controlling an electrical quantity, such as voltage, of an alternating current circuit.

This application is a division of my copending application, Serial No. 135,483,,filed April 7, 1937, for Electronic regulators, and assigned to the Westinghouse Electric 8: Manufacturing Com- D y.

One object of my invention is to provide an electronic regulator that is reliable and accurate in operation and that is rapid in response to changes in the regulated quantity.

Another object of the invention is the provision of an electronic regulator having a detector circuit that is quick in its initial response to variations in the regulated quantity from the desired value and that is thereafter recalibrated to insure an accurate final adjustment.

A further object of my invention is the provision of an anti-hunting circuit that is promptly responsive to variations in the regulated quantity.

Other objects and advantages of my invention will appear from the following description of one preferred embodiment thereof, reference being had to the accompanying drawing, in which Figure 1 is a diagrammatic view of apparatus and circuits illustrating a preferred embodiment of the invention, and

Fig. 2 illustrates curves showing certain relationships between component voltages of the system.

Referring to the drawing, a machine I, such as an electric generator, is provided with an armature winding 2 for supplying an alternating current energy to a circuit represented by conductors 3, 4, 5, and with a field winding supplied with energy from an exciter generator I having an armature winding 8 and afield wind-- ing 9. The field winding 9 is supplied with unidirectional current from an alternating current source, such as conductors 3 and 5 through conductors l2 and I3, and a transformer I4 as supplied by the tube rectifiers l6 and I1.

The current output of the rectifiers l6 and I1 is controlled bya detector tube [8 and an amplifying or control tube [9 in accordance with the voltage between conductors 3 and 5 as supplied to the primary winding 22 of a transformer 23 through conductors I2 and 13. The energizing circuit for the exciter field winding 9 extends from the central point ll of the transformer secondary winding l5, by conductor 24 through the winding 9, switch 25, conductor 23, the cathodes 21 and anodes 28 of tubes l6 and I1, re-

spectively, to the opposite terminals of the winding 15, the tubes I6 and I1 providing full wave rectification of the current supplied by the transformer l4 in a well known manner. A control potential E0 is supplied to the grids 29 of tubes I6 and I! to govern the current output through these tubes to the field winding 9. The potential E0 is determined by the tubes l8 and I9 and is made up of two components E1 and E2, E1 being the voltage drop across a resistor 3|, and E2 being the voltage drop between a terminal 33 and an intermediate point 34 of a resistor 35 that is supplied with uni-directional current through a full wave rectifier 35 from a transformer secondary winding 31 that is responsive to variations in the voltage between the power circuit conductors 3 and 5. The grid circuit of tubes I6 and I1 extends from the cathodes 21 through conductor 26, the resistor 3|, the portion of the resistor 35 that is between points 33 and 34, conductor 38, and alternate halves of the secondary winding 39 of a phase shifting transformer to the respective grids 29 of the tubes l6 and II.

'An alternating current wave of voltage E: is

introduced intothe control circuit by the transformer winding 33 that is coupled to the primary winding 45. This voltage is displaced 90 electrical degrees from the wave of the anode voltage of the tubes l3 and I! in a wellknown manner by a network connected to the secondary wind ing 42 of the transformer [4, the opposite terminals of which are connected respectively to a condenser 43 and a resistor 44 that are connected in parallel and to one end of the primary winding 45, the other end of the transformer primary winding45 being connected to the midpoint 46 of the winding 42,

The primary control of the grid circuit of the rectifier tubes l5 and I1 is the amplifyingor control tube l9 having a cathode 41 that is connected to the negative terminal 48 of the resistor 35, a heating element 49 that is'supplied with current from the-winding 52 of the transformer 23, a control grid 53, an anode 54, and an anode grid 55 that is connected by conductor 55 to an intermediate point 51 on the resistor 35. The anode 54 is connected by conductor 53 through the resistor 3l to the positive terminal of the resistor 35.

The tube I8 is a two-element tube having an anode 59 that is connected through a resistor GI to the positive terminal 33 of the resistor 35 and a filament cathode 62 that is connected to be heated from a transformer winding 63 in accordance with the voltage E4 that varies with the of three components E5, E6 and E1, the voltage E being the voltage across the tube I8, the voltage Es being a unidirectional voltage impressed upon a condenser 65 through a full-wave rectifler B6 supplied with'alternating voltage from a transformer winding 61 that varies in accordance with the regulated voltage ER, and the voltage E1 being that developed across an anti-hunting resistor 68. The circuit from the cathode 41 including these voltage components is traced through conductor H to junction point 64, conductor I2, through tube I8, conductor 73, condenser 65, conductor 14' and resistor 68 to the control grid 53.

The voltage across the anti-hunting resistor 68 is determined by an anti-hunting network to the terminals TI and 78 of which a unidirectional voltage is supplied through a full-wave rectifier 15 from the transformer winding 16 that varies in accordance with the regulated voltage ER. A resistor l3 and condenser 8| are connected in parallel between the terminals ll and 18 of the network to form a filter circuit that operates in a well known manner to give a unidirectional voltage without alternating current ripple. The circuit through the network between the terminals TI and it extends through a reactor 82, resistor 83, to a junction point 84, thence through two branch circuits, one of which includes a condenser 85, and the other of which includes a condenser 86 and the resistor 68 in series, to the terminal Tl. When the regulated quantity ER is at any constant value, a constant charge exists on the condenser 85 determined by the voltage between terminals H and 5/8, the charge being ce'astant so that no current flows through the 8} si -hunting resistor 68 and the potential drop thereacross is zero.

When the generator is started, the switch in the exciter generator field winding circuit may be moved to engage the contact 81 to temporarily energize the exciter field winding from the armature winding 8 through a resistor 88 until the machine has built up a substantial voltage,

after which the switch member 25 is moved to its illustrated position. In this position, field current flows from the transformer winding I5 through the tubes l6 and H which rectify alternate half cycle waves as controlled by the potential of the grids 29. Assuming that the regulated voltage ER is constant at its desired value, the unidirectional voltage from the rectifier 38 that is impressed upon the resistor will be constant and the voltage component E2 will be constant. The voltage E4 determining the heating of the detector tube cathode 82 is also constant so that the current flow through the tube and the voltage drop E5 thereacross is constant. Likewise, the

voltage component E6 that is determined by the voltage Ea through rectifier 66 is constant and the voltage component E1 is zero, as above explained, thus permitting a constant current to flow through the control tube l9 causing a constant voltage drop E1 which combined with a constant component E: supplies a constant output control voltage E0 for controlling the rectifier tubes l6 and I1. 2:.

If, for example, the voltage Ea now decreases in value because, for example, of a sudden increase in load ,on the generator i, the voltage component Es correspondingly drops. As above noted, the voltage Es between the cathode 41 and control grid 53 of the tube i9 is made up of three components E5, E6 and E7. The component E7 is zero at the initiation of a change in the voltage ER. and the component E5 is substantially constant for a short time interval thereafter owing to the fact that an appreciable time is necessary for a change in the heating of the cathode 62 after a change in the voltage E4 as indicated by the curve E5 in Fig. 2. Therefore the initial change in the regulator voltage Ea, which effects a correspondingly sudden decrease in the voltage component Es causes the potential of the control grid 53 to become immediately more positive, permitting a greater flow of current through the tube I9 from the positive terminal 33 of the resistor 35 through conductor 3|, conductor 58, anode and cathode 54 and 41, and conductor H to the negative terminal 48, causing a sudden inbrease in the voltage E1. This change in the voltage component E1 increases the output voltage E0 of the detector circuit, making the voltage of the rectifier tube grids 29 more positive so that the tubes l8 and I! will pass more current through the field winding 9 of the exciter generator and increase the excitation of the generator I and the voltage between conductors 3 and 5.

At the same time that the voltage component Es is reduced in response to a reduction in the regulated voltage E a wave of stabilizing voltage component E7 (see Fig.2) is developed across the resistor 68 in a direction to make the grid 53 still more positive for a short duration of time so that the increase in the voltage Ea, which is the sum of the voltage components E5, E6 and E7 is increased, thus making the grid more positive to increase the current flow therethrough and cause the voltage component E1 to vary as shown in Fig. 2, to increase the current flow through the tubes l8 and I1 and the exciter field winding.

The curve E1 in Fig. 2 shows the general nature of the voltage change across resistor 3| during the initial part of the regulating action. It will be noted that the voltage E2 makes a rapid change, influenced in part by the stabilizing voltage wave E1 which gives a temporary infiuence to the shape of the curve.

The explanation of the voltage wave E7 will be readily understood in that as the potential Ex is reduced the unidirectional potential across terminals 11 and 18 from the full-wave rectifier 15 is correspondingly reduced, thus reducing the potential across the terminals of the condenser 85. This causes a circuit to how from the condenser through condenser 86 and resistor 68 to the terminals TI and 18, thus making the left-hand or grid end of the resistor 88 more positive than the terminal 11 so long as this discharging current fiows from the condenser 85.

After a short time interval during which the corrective action occasioned by the change in the value of the voltage component E1 is under way, the decrease in the heating of the cathode 62 in response to the decrease in the regulated voltage Ea causes the current flowing through the tube l8 to decrease, thus increasing the voltage component E: which has the effect of increasing the potential on the control grid 53 of the tube l9 to recalibrate this tube for the new load condition requiring an increased value of E0 in order to maintainthe regulated voltage Ea constant at the new generator load. It will in the voltage E4 to become eiiective, the inaaraeco v variations in the said characteristic in a direcbe noted in tracing the circuit from the cathode 41 through the tube It and the condenser 85 to the control grid 53 that the voltage component, E5 is positive while the voltage component Es is-negative so that the alphabetical sum Ea is the arithmetic difference between these two quantities. Thus, an increase in the voltage component Ea raises the potential of the control grid 53 and a decrease in the control potential E6 raises the potential of the controlgrid 53.

An increasein the regulated voltage Ea causes the reverse operation of the several component parts of the detector circuit to decrease the voltage E and correspondingly the excitation current through the rectifier tubes l and [1. For example, upon an increase in the regulated voltage En, the unidirectional output voltages from the full wave rectifiers 66, I5 and 36 correspondingly increase, as does the voltage component E4 for controlling the heating of the cathode 62 of the detector tube l8. The initial action of the increase in the voltage components Ec lowers the potential of the control grid. 53, since the potential E5 across the detector tube 18 is substantially constant for a short period of time. The flow of current to the condenser 85 to increase the charge thereupon causes a current to fiow through the stabilizing resistor 68 in a direction to lower the potential of the control grid 53 with respect to the terminal Tl, thus reversing the conditions represented in Fig. 2 in that the stabilizing wave E1 will be negative and the voltage component E1 will decrease. Likewise, after the time necessary for the change crease in the heating of the cathode 62 will cause more current to flow through the tube 18,

thus decreasing the voltage drop thereacross and causing the voltage component E5 to correspondingly decrease and thus recalibrate the tube 9 for the new required values of E5 and Es.

Many modifications may be made-in the apparatus and circuits illustrated and described within the spirit of my invention. I do not wish to be limited otherwise than by the scope, of

the appended claims.

I claim as my invention:

1. In a regulating system for controlling an electric characteristic of an alternating current power circuit, in combination, means including a grid controlled rectifier tube for supplying a unidirectional current-from the power circuit, means for controlling the output of said rectifier tube for controlling said characteristic comprising a detector tube having an anode and a filament cathode sensitive to the said characteristic, a grid controlled amplifier tube governed thereby, and additional means sensitive to variaing said amplifier tube.

2. ma regulating system for regulating an electrical characteristic of an alternating current power circuit, in combination, means including a grid controlled rectifier for supplying a unidirectional current for controlling said characteristic, means for controlling the current out- ,put of said rectifier in response to the said characteristic comprising a grid controlled tube, means for introducing a plurality of voltage components into the grid circuit of said tube, one of said components varying promptly with variations in the said characteristic in a direction to effect a correction thereof, and another oi said components varying more slowly with' tion to effect a correction thereof.

3. In a regulating system for controlling an electric characteristic oi. an alternating current power circuit, in combination, means including a grid controlled rectifier for supplying a unidirectional current for controlling said characteristic, means for controlling the current output of said rectifier in response to said char- 'acteristic comprising a grid controlled tube,

means for controlling the grid potential or said tube including full wave rectifying means responsive to the said characteristic and a filament cathode diode detector tube also sensitive to the said characteristic. A

4. In a regulating system for controlling an electric characteristic of an alternating current power circuit, in combination, means including a grid controlled rectifier for supplying a unidirectional current, for controlling said characteristic, means for controlling the current output of said rectifier in response to said characteristic comprising a grid controlled tube, and a filament cathode diode detector tube sensitive to the said characteristic, means for controlling the grid potential of said tube including a plurality of means for introducing control voltage components in series in the grid circuit of the tube. one of said means introducing a voltage component that is promptly responsive to variations in the said characteristic, another of said means introducing a voltage component that is controlled by said detector tube, and another 01. said means introducing a voltage component of short duration that varies in direction and degree with the change in the said characteristic and in a direction to increase the rate of response in the correction of the said characteristic.

5. In a regulatingsystem for controlling an electric characteristic of an alternating current power circuit, in combination, means including a grid controlled rectifier for supplying a unidirectional current for controlling said character- 'istic, means for controlling the current output of said rectifiercomprising'a'filament cathode diode detector tube that is responsive to the voltage of said alternating current power circuit and a grid controlled amplifier tube, a plurality of means for introducing voltage components in series in the grid circuit of the amplifier tube comprising means for introducing a voltage component that is responsive promptly to variations in the voltage of said alternating current power circuit, means sensitive to changes in the voltage ofgsaid alternating current power circuit for introducing a surge potential of short duration in a direction to increase the rate of correction of the voltage of said alternating current power tions in the said characteristic for also infiuencran-cult and means including said filament cathode diode detector tube that is responsive to the voltage 01 said alternating current power circuit for gradually recalibrating the amplifier tube after the initial correction in the regulated voltage.

6. In a regulating system for controlling an electric characteristic of an alternating current power circuit, in combination, means including a grid controlled rectifier for supplying unidirectional current for controlling said characteristic, means for controlling the current output oi said rectifier means comprising a filament athode diode detector tube that is responsive to the voltage of said alternating current power circuit and a grid controlled amplifier tub controlled thereby, means for governing the amplifier tube in response to a change in the voltage of said altermating current power circuit prior to the inherent time interval required for respo se of said diode tube, comprising means for int 'oducing a voltage component into the grid circuitoi said amplifier tube that is promptly responsive to variations in the alternating current power circuit voltage and means for introducing a surge voltage of short duration into the grid controlled circuit upon a variation in the power circuit voltage in a direction to increase the rate of correction of the voltage of said alternating current power circuit. 7

7. In a regulating system for regulating an electrical characteristic of a dynamo-electric machine having a field winding and means for supplying a unidirectional exciting current to the field winding comprising a grid controlled rectiher, in combination, means for controlling the output current of the rectifier comprising a grid governed control tube, means for controlling the control tube grid voltage comprising a filament cathode detector tube that is sensitive to variations in the said characteristic, and means for introducing a voltage component into the grid circuit of said control tube that varies more promptly with variations in the said characteristic than does the detector tube.

8. In a regulating system for regulating an electrical characteristic of a dynamo-electric machine having a field winding and means for supplying a unidirectional exciting current to the field winding comprising a grid controlled rectifier, in combination, means for controlling the current output of said rectifier in response to variations in said characteristic comprising a grid controlled tube, means for controlling the grid potential of said tube including a plurality of means for introducing control potentials in series in the grid circuit of said tube that are sensitive to the said characteristic and that are aeration characterized by different rates of response to variations in the said characteristic,

1. a regulating system for controlling an electrical characteristic of a. dynamo-electric machine having a field winding and means for supplying a unidirectional exciting current to said field winding comprising a grid controlled rectifier, in combination, means for controlling the output current from said rectifier in response to variations in said characteristic comprising a grid controlled tube, means ior introducing a plurality of voltage components into the grid circuit of said tube, one of said components varying promptly with variations in said characteristic in a direction to effect a correction thereof, another of said components varying more slowly with variations in said characteristic in a direction to efl'ect a correction thereof, and another of said components effecting a temporary impulse in a direction to efiect a correction in said characteristic.

10. In a regulating system for controlling an electrical characteristic of a dynamo-electric machine having a field winding and means for supplying a unidirectional exciting current to said field winding comprising a grid controlled 'rectifier, in combination, means comprising a grid controlled tube and a cathode filament diode detector tube sensitive to the said characteristic for controlling the current output of said rectifler, means for controlling the grid potential of said tube including a plurality of means for introducing control voltage components in series in the grid circuit of the tube, one'oi said means introducing a voltage component that is promptly responsive to variations in the said characteristic, and another of said means introducing a voltage component that is controlled by said detector tube.

FINN H. GULLIKSEN. 

